title: Photodetachment and photodissociation of the linear OCuO- molecular anion: energy and time dependence of Cu- production.
abstract: A photodissociative study of CuO2(-) is presented using a combination of energy and time domain photoelectron spectroscopy. Ion source conditions are used that solely produce linear OCuO(-). Photodissociation of this isomer to produce Cu(-) + O2 is conclusively demonstrated at wavelengths between 765 and 340 nm. Nanosecond pulsed photoexcitation at wavelengths shorter than 340 nm produces single photon detachment transitions from the first excited state of CuO2(-). At longer wavelengths narrow Cu(-) fragment transitions are observed as a result of a sequential two photon process. In addition, the longer wavelengths produce a weak, broad two photon dependent signal, the result of detachment of the dissociating linear isomer. Time resolved pump-probe measurements reveal a long timescale growth (up to 150 ps) of the Cu(-) fragment yield, consistent with the unfavorable starting geometry for the dissociative process and indicating a potential energy surface which has one or more substantial barriers to dissociation.
authors.affiliation: Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, 63130 USA. mabbs@wustl.edu.
authors.forename: Richard
authors.initials: R
authors.lastname: Mabbs
authors.forename: Nicholas
authors.initials: N
authors.lastname: Holtgrewe
authors.forename: Diep Bich
authors.initials: DB
authors.lastname: Dao
authors.forename: Joshua
authors.initials: J
authors.lastname: Lasinski
mesh_terms: D000838:Anions / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes; D056951:Photoelectron Spectroscopy; D011789:Quantum Theory; D013997:Time Factors
chemical_list: D000838:Anions; D003300:Copper; D010100:Oxygen